Believe it or not, the curved screen on the Samsung Galaxy Round smartphone isn’t just a marketing gimmick: The curvature actually causes a series of optical effects that result in improved contrast, color accuracy, readability, and overall image quality — especially under ambient light that usually makes smartphone screens almost unreadable, such as daylight or fluorescent office lighting.

This new information about curved displays comes from Raymond Soneira, who is one of the few authorities on display technology, image quality, and color calibration. From the story on his site, it sounds like Samsung gave him a Galaxy Note 3, the Galaxy Round (which is the Note 3 but with a curved display), and a standalone, free-standing OLED display from the Round (which he could bend and flex to his heart’s content). While he hasn’t yet produced his usual slew of images and graphs, it’s clear that he’s very surprised by the massive gain in image quality afforded by the curved display.

For the most part, curved displays are better than their flat siblings due to drastically different reflectance. To begin with, hold your smartphone in front of you, with the screen off. If you’re outside or in the office, you will notice a huge amount of reflections — your face, overhead lighting, etc. These reflections don’t go away when you turn the screen on; they are merely masked by the patterns displayed on the screen, and the brightness of the display. This is why image quality is generally so atrocious when there’s a lot of ambient light, and why display brightness is valued so highly. Manufacturers are making big strides in reducing reflectance — by introducing new filters, reducing the distance between the display and the protective front glass, etc. — but ultimately, a flat piece of black-backed glass is always going to be pretty reflective.

The Galaxy Round display is only slightly curved along the horizontal plane — the edges are 2.6mm (0.1 inches) higher than the center of the screen — but, believe it or not, this is enough to cause the same magnification as a convex hand mirror. This magnification (and the curvature in general) results in huge improvements almost across the board, from more saturation to better color accuracy and readability. (Read: UCLA creates flexible OLED display that can be stretched to double its normal size, folded in half.)

Most of these gains come from the magnification, which causes three important effects. First, by magnifying your face (by two or more, depending on your viewing distance), less light from behind your face is reflected by the display. Your face is usually shadowed, and doesn’t cause much reflection. Second, the magnification process also dims the reflection of your face (the light is being spread out by the magnification), resulting in less reflectance. Ironically, this also means it isn’t so easy to use a curved display for personal grooming. Finally, at a typical viewing distance of 16 inches (40 cm), the magnification factor is so large that your face becomes a featureless blur, again reducing the amount of noticeable/disruptive reflectance.

Beyond magnification, the simple fact that it’s a curved display means less non-direct light reflects of the screen — and any light from behind you that does hit the screen gets reflected away from your eyes (specular reflection).

All of these factors combine to create a display that, according to Soneira, is massively improved over the Galaxy Note 3 — which itself has a very highly regarded display. The reduced reflectance should also mean that display brightness can be reduced, increasing battery life, though it isn’t clear if the Galaxy Round does this. In fact, from the marketing materials, it isn’t even clear if Samsung is aware of the advantages of curved displays — though, following Soneira’s glowing analysis, the Korean chaebol surely knows now.

Tagged In

All this sounds good, but doesn’t it imply there is a distance that is a sweet spot? On a flat screen, display readability seems to fall off linearly with distance – when I am navigating with my phone clipped to my dash, it’s hard to read but not impossible – bigger text and lines fixes the problem.

If magnification effects are so prominent, won’t a curved screen require the phone to be at a fixed distance for legibility?

http://www.mrseb.co.uk/ Sebastian Anthony

It’s just magnification of reflections, not of the image on the screen.
Soneira says it’s 2x magnification at 8 inches (close), and much more magnification at 16 inches (normal’ish viewing distance).

BillBasham

Excellent clarification – thank you!

cougar3429

Asking genuine questions about the article = down votes. I’m curious what most peoples’ intent is when they vote down a comment. Disagreement? Disgust? Moral Superiority? Yeah, that one sounds about right.

Frank Lindsey

I’ve really ignored any information about the curved screen, until now, thinking it was all hype. Interesting article, i’ll have to check out the phone when I get a chance.

mrseanpaul81

I was in the exact same boat! That is definitely something I need to check as well

MadisonHJ

That is the most life-like mannequin I’ve ever seen holding those two phones in the picture.

beatles

wow that curve, the girl!
that’s all about it

AdamRadzik22

Very interesting article…I always thought it was purely a marketing gimmick as well. Thank you.

Abstract
This paper addresses projected image Distortion in a cinema setting. Several types of distortions are defined and examples are presented to show that the degree of distortion in the image can be calculated based on the theater geometry as well as the film format and projector lens specifications.
This paper concentrates on inherent distortion values that typically affect the overall shape of the picture area and the relative shapes of all subjects being viewed as well as the audience’s perception of imaged picture quality. Since distortion changes only the shape of objects in the picture and not how well the viewer can see them, there is little basis for objectively derived design limits. Further, when viewing a
real scene that does not contain a perfect rectilinear test grid, the eye accommodates small amounts of distortion, which is therefore not perceived. However, moderate to severe amounts of distortion, and particularly distortion in
memory objects such as curved horizons and leaning or curved flagpoles, is disturbing to viewers.”

“No distortion effects based on viewing angle were considered since these are dependent on the location of the observer in the theater. The distortions defined herein are only dependent on the physical geometry of the screen in reference to the projector position and orientation as well as the lens focal length.”

First, this paper doesn’t compare curve vs. flat screens instead it concentrate on how to calculate the distortions. In some cases flat screen is better and in some cases curve screen is better an it is highly dependant on physical constrains.

Second, this paper is about projection screen, WITHOUT REFLECTIONS on it, placed relatively far from the viewer and the projector in relatively big room. Here we have small screen at arm length and with many reflections on it.

The design constrains (curved vs flat) are not the same on big projection screen, relatively big HDTV screen, and relatively small screen tablet or phablet and small screen on your iPhone.

Robiara Ubiratan Becker

In a cinema setting, yeah, that’s a place saturated with reflections onto the screen!!!!

Sensational title and sub-title. Read the article and you will notice that their main complain is mismatched expectations.

“With really large screens, one of the biggest advantages is being able to “focus” more light toward the audience. Another is REDUCING OPTICAL DISTORTIONS
when using certain projection lenses. There’s also a potential “naturalness” to an image that has every part equidistant to your eyeballs. But perhaps the most notable benefit is the ability to fill a massive percentage of a viewer’s field of view. Sitting in the right seat, you could have the image practically wrapped around you.”

This is the author’s expectations and relatively (to projection screen) small HDTV can’t deliver. Again is not applicable for smart phone screen.

You really didn’t read the article or you couldn’t comprehend it.

Dozerman

Looks like every smartphone iin the next five years will have a curved display…

“This doesn’t mean that we’ll suddenly
see computer chips made out of graphene instead of silicon, though — we still
haven’t found a way of giving graphene a bandgap, which means it’s actually
fairly useless as far as digital computing goes.”

Use of this site is governed by our Terms of Use and Privacy Policy. Copyright 1996-2016 Ziff Davis, LLC.PCMag Digital Group All Rights Reserved. ExtremeTech is a registered trademark of Ziff Davis, LLC. Reproduction in whole or in part in any form or medium without express written permission of Ziff Davis, LLC. is prohibited.